A number of different propulsion and steering assemblies have been developed wherein the basic components are formed as a one-piece or integrated unit in order to eliminate alignment problems associated with prior art assemblies arising when the different components are assembled together during manufacture or outfitting of the basic boat. Reference is made, for example, to U.S. Pat. No. 3,003,458 (Starns, Jr.) wherein an inboard boat propulsion and steering assembly is disclosed which includes a propeller shaft "log" or housing, a mounting plate, a rudder shaft "log" or housing and a downwardly depending shaft support strut carrying a propeller shaft bearing, all formed as an integral unit. It will be appreciated that this integral unit inherently provides proper alignment between the propeller shaft log and the propeller shaft bearing. The integral unit, with the propeller shaft and rudder inserted therein, can be installed as one piece, and when the unit is installed, only installation, alignment and connection of the engine and mounting of the propeller on the propeller shaft remain in order to complete the propulsion and steering assembly. Other examples of integrated units of this general type include U.S. Pat. Nos. 2,064,463 (Crosely, Jr.); 2,630,094 (Hacker); 2,895,446 (Upton); 2,934,034 (Grzesnikowski); 4,040,378 (Blanchard); 4,046,096 (Liaaen); and 4,236,478 (Mansson).
As discussed below, one aspect of the present invention concerns the provision of a unitary or integrated propulsion and steering apparatus with improved trust take-up characteristics. There are, of course, many patients generally relating to thrust bearing assemblies for boats and these include U.S. Pat. No. 2,521,368 (Hingerty, Jr.) which relates to a thrust bearing assembly adapted for use in a conventional (non-integrated) marine propeller drive assembly and including a pair of oppositely effective bearing devices.